J. Mater. Sci. Technol. ›› 2024, Vol. 189: 146-154.DOI: 10.1016/j.jmst.2024.01.002

• Research Article • Previous Articles     Next Articles

Double Z-scheme in SnO2/SnS2/Cu2SnS3 heterojunction for photocatalytic reduction of CO2 to ethanol

Feng Wang1, Shunxin Zhang1, Wenhao Jing1, Haoran Qiu, Ya Liu*, Liejin Guo*   

  1. International Research Center for Renewable Energy, State Key Laboratory of Multiphase Flow, Xi'an Jiaotong University, Xi'an 710049, China
  • Received:2023-09-10 Revised:2023-12-27 Accepted:2024-01-03 Published:2024-08-01 Online:2024-01-12
  • Contact: *E-mail addresses: . yaliu0112@mail.xjtu.edu.cn (Y. Liu), lj-guo@mail.xjtu.edu.cn (L. Guo)
  • About author:1 These authors contributed equally to this work.

Abstract: Photocatalytic reduction of CO2 to chemical fuels enables a sustainable way of reducing carbon emissions but faces a high reduction potential due to the high stability of CO2 molecules. Here, we prepared a SnO2/SnS2/Cu2SnS3 double Z-scheme heterojunction photocatalyst, in which SnO2, SnS2, and Cu2SnS3 absorb ultraviolet, visible, and near-infrared light, respectively. Based on the comprehensive analysis of in-situ X-ray photoelectron spectroscopy and photo(chemical) characterizations, we find that the photogenerated electrons would transfer from SnO2 to SnS2 to Cu2SnS3. The optimized SnO2/SnS2/Cu2SnS3-0.3 double Z-scheme heterojunction could achieve 28.44 µmol g-1 h-1 ethanol yield and 92% selectivity, which is roughly 3 folds higher than SnO2/SnS2 single Z-scheme heterojunction. By using in-situ diffuse reflectance infrared Fourier-transform spectroscopy, we observe that ethanol is produced through a *COCOH pathway, in which Cu2SnS3 would decrease the activation energy barrier from *COOH to *CO.

Key words: CO2 reduction, Photocatalysis, Z-scheme, Ethanol